Reduction Leaching of Manganese Nodules with Copper Matte.

Abstract

The leaching characteristics of manganese nodules were investigated in dilute hydrochloric acid solution by using copper matte as a reductant. The copper matte has been found to be an effective reductant for extracting more than 96 % of Mn, 95 % of Ni, 91 % of Co, 88 % of Cu, and 36 % of Fe when leached in 2.5 M HCl at 70°C for 2 h. The dissolution of Mn, Co and Ni depends on the amount of added copper matte. The ratio of liquid and solid is important factor on the extraction of metals during leaching. The dissolution of Mn, Co, Ni and Cu is increased with the increase in temperature of the leachant. The rate of Mn, Co, Ni and Cu leaching from manganese nodules in the presence of copper matte is limited by both the surface chemical reaction and pore diffusion processes. The activation energies for Mn, Co, Ni and Cu were 73, 53, 72 and 242 kJ/mol, respectively.